Pathway to Insoluble Aggregates on the Refolding of a Single-chain Fv Antibody: Morphological Changes of Aggregated Protein on Refolding

In vitro aggregated single-chain Fv antibody (scFv) was analyzed by attenuated total reflectance Fourier transform infrared spectra and scanning electron microscope images. The spectroscopic results demonstrate that the formation of (beta)-strands is a first trigger to the off-pathway toward insoluble aggregates, which is independent of redox condition; however, the morphology of the insoluble aggregates is strongly influenced by the environment in which scFv is aggregated.